Air conditioning unit having a reversible fan wheel



Jan. 20, 1948. H. F. HAGEN f 2,434,847

AIR CONDITIONING UNIT HAVING A yRBTVIIRSIBIJIE? FAN WHEEL' Filed March 9, 1945 iff/ f/ lvm 1N VENTOR. Hamm@ HAGEN 'Omml/ 7, @aux f4 fm2/vs y the conditioned air is heatedair.

Patented Jen. 2o, 194s AIR CONDITIONING UNIT HAVING A REVERSIBLE FAN WHEEL yHarold F. Hagen, Wellesley, Mass., assignor, by mesne assignments, to Westinghouse Electric Corporation, a corporation of Pennsylvania Application March 9, 1945, Serial No. 581,868

3 Claims. l

This invention relates to air conditioning systems and apparatus, and relates more particularly to systems and apparatus in which outdoor air is conditionedat a central point, then supplied under pressure to remote points and there mixed with recirculate'd air and distributed.

vThe W. L. Fleisher Patent No'. 1,983,023 discloses an air conditioning system in which out door air is chilled, in summer, to a relatively low temperature in a central conditioner, then supplied under pressure through small ducts to remote distributing units in which `recirculated air is drawn in by local fans and mixed with the chilled air for adding sensible heat thereto, and

distributed. A

The Vernon Cano Patent No. 1,995,667 discloses an air conditioning system similar to that of the said Fleisher patent except that instead of using fans for drawing in the recirculated air at the distributing units, the conditioned air passes through ejector nozzles which act to induce the flow of recirculated air Disadvantages of systems such as are disclosed in the said Cano patent are that when very small pipes or ducts are used for supplying the conditioned air to the distributing units, as is convenient in the installation of air conditioning systems in buildings already constructed, the air pressure drops in the air supply pipes are so great that air compressors have to be used at the central conditioners for supplying the great air pressures required, and the velocity of the compressed air is so great that vibrations and resulting noises are produced in the supply pipes and in the distributing units.

Disadvantages of ejector nozzles for inducing the new of recirculated air are that their eiiciency is low, and the total, volume discharged from the distributing units varies with the volume of conditioned air supplied to the units. For the reasons stated in the said Fleisher patent it is highly desirable that the volume of air supplied by the distributing units remains constant at all times A further disadvantage of the types of systems disclosed by the said Fleisher and Cano patents is that they were designed primarily for air cooling and do not provide proper distribution when ence to the Cano patent it is seen thatrthe recirculated air is always drawn into the distributing units along the floor line, and that the mixed conditioned and recirculated air is discharged verticallyfrom the tops of the units While this is satisfactory for the distribution of chilled air With referin the cooling season, it is not satisfactory for the distribution of heated air in the heating season. This because the heated air rises in convection currents with the result that the space above the occupants of a room is overheated with the floor space inadequately heated.

This invention provides local distributing units generally similar to the one of the said Cano patent except that fans instead of ejectors, are used for drawing in the recirculated air.

A feature of this invention resides in providing fans arranged also for drawing in the conditioned air thus aiding in overcoming the pressure drop in small supply ducts,and obviating the necessity for using air compressors at the central conditioners.

Another feature of this invention resides in the provision of reversible fans in the distributing units, which for distributing chilled air in summer, draw in recirculated air at the floor line, draw in conditioned air, and discharge the mixed air from the tops of the units, and for distributing heated air in Winter, draw in recirculated air at the tops of the units, draw in recirculated air, and discharge the mixed air in the floor zone.

the front wall removed, of the unit of Fig 2.

Referring first to Fig. l, the central air conditioner 5 in the .cellar 6 of the building 1, in-

cludes conventional apparatus such as disclosed in the said Fleisher and Cano patents, for dehumidifying and cooling the outdoor air in summer, and for heating and humidifying the air in winter.

The blower 9 draws the outdoor air through the conditioner 5 and supplies it under pressure through the small ducts or pipes Ill into the lower portions of the local air distributing units Il'.' The ducts I0 are suiilciently small that they can easily be placed between the walls of an existing building as illustrated by Fig. 1.

Each local distributing unit Il comprises a substantially rectangular, sheet metal casing having the grille I2 in its upper wall, and the grille I3 in the lower portion of its front side.

The fan wheel Il having the rotary shaft I5 and the blades I6, is supported within the fan casing I1 in the lower portion of the unit behind the grille I3. The walls cf the casing I1 form an air passage I9 connecting with the lower grille I3; form an air passage I9 connecting with the air supply duct I0, and form a third passage 20 which connects with the space between the transformation plates 2|.

The upper ends of the plates 2l contact the side walls of the unit II below the conventional heat exchanger 22 which extends crosswise the unit between the passage 20 and the upper grille I2.

The shaft I5 is supported between the end bearings 23 and is rotated by the electric motor 24 which is supported upon the bracket 25 at one end of the unit. The electric switch 26 is Wired into the motor and supply circuit as is conventional, for reversing the direction of rotation of the motor.

The damper 2l vin the duct I0 is adjustable by the control 2 for varying the volume of conditioned air through the passage I9.

In operation, the blower 9 draws conditioned air from the conditioner 5 and blows it under pressure through the ducts I0 into the passages I9 in the units II. In the heating season, the conditioner will supply filtered, heated and humidified air, at which time steam or other heating uids will be supplied to the tubes 29 in the heat exchangers 22. In the cooling season, the conditioner E will supply ltered, chilled and dehumidied air to the ducts I0, and chilled water or other suitable refrigerated uids will be supplied to the heat exchangers 22.

The fan wheels I4 will be rotated by the motors 24 in the cooling season, in a direction to draw recirculated air through the grilles I3 and to blow the mixed chilled and recirculated air through the heat exchangers 22 and through the upper grilles l2 into the rooms where the units are located. The broken line arrows of Fig. 2 illustrate the directions of air ow at this time.

The fan wheels I4 will be rotated in the heating season in the opposite direction and will draw recirculated air in through the upper grilles I2, and will blow the mixed conditioned and recirculated air through the grilles i3 into the rooms.

In both the cooling vand heating seasons, the fans in the distributing units act as induced draft fans for aiding in overcoming the resistance of the ducts I0.

The control 28 can be actuated by hand or under thermostatic control for varying the volume of conditioned air supplied to each unit. This control varies the proportion of conditioned air to recirculated air, the total volume of air discharged from the unit being constant as is desired for comfort.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, as modifications' thereof can be suggested by those skilled in the art without departure from the essence ofthe invention,

What is claimed is:

1. An air conditioning unit having an upper opening and a lower opening, a centrifugal fan in said unit, said fan having a reversible fan wheel and having a casing therearound, said casing having two peripheral openings therein, means defining an air passage connecting one 0f said peripheral openings with said upper opening, means defining a second passage connecting the other of said peripheral openings with said lower opening, said unit having a primary air inlet opening, said fan having aI fan inlet opening between said peripheral openings, and means dening a third air passage connecting said fan inlet opening with said air inlet opening, said means isolating the air in each of said passages from the air in the others of said passages except through said fan.

2. An air conditioning unit according to claim 1 in which the fan inlet opening is a peripheral opening in said casing.

8. An air conditioning unit according to claim 1 in which the upper and lower openings extend substantially the same distance longitudinally of the unit, and the fan wheel and the rst and second passages extend the lengths of the upper and lower openings.

HAROLD F. HAGEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED sTA'Es PATENTS Number Name Date 341,218 Blakely May 4, 1886 938,781 McDonough Nov. 2, 1909 1,919,646 Woolhouse July 25, 1933 2,208,890 Bowers July 23, 1940 1,983,023 Fieisher Dec. 4, 1934 2,345,536 Keep Mar. 28, 1944 1,890,521 Mack Dec. 13, 1932 2,021,583 Whiteley Nov. 19, 1935 FOREIGN PATENTS Number Country Date 291,007 Great Britain Aug. 2, 1928 

